Holter Monitors are utilized by the cardiologists to diagnose arrhythmias associated with the heart. Holter monitors are connected to the patient and the heart is monitored for usually 24 hours to detect arrhythmias that are intermittent and difficult to isolate. The recording of the electrical activity of the heart during the 24 hours is reviewed and any arrhythmia that may have occurred within the 24 hour period is able to be diagnosed.